Eleven years later and
Mount & Blade Warband is still one of the very best (
GOG,
Steam). It is one of my most played games, ever. It takes place in a fictional medieval realm. You create your character, pick your backstory (nobles get more starting money and charisma, smiths get a bonus to strength, hunters get tracking and movement speed bonuses, etc), pick a town, and then you're let loose. You can hire a few guys and roam around the countryside with your merry men, attacking bandits (or become bandits!) and complete jobs for the local towns and villages such as escorting caravans or herding cattle. You can sign up to fight as a soldier in a lord's army, climbing up the ranks until you've got your own set of armor and some money, and can either pledge your loyalty to a king and become a full fledged vassal, or leave the army with your armor and your sack of money to strike out on your own. You can build a trading empire, establishing businesses in towns, trading goods between towns and villages for profit. You can use your wealth to build an army and climb the ladder, becoming a lord of a village, garrisoning your castle, or holding a town and managing the region. You can develop your relationship with other lords, convince them to aid you in your plans, frame other lords to kick them out of the area, and go to war with the other nations. You can establish your own nation as well, and so on.
Mount & Blade is really easy to mod. Unlike games like say, Skyrim and Minecraft, you don't need a mod manager and need to spend dozens of hours trying to find the right mod order or resolving conflicts and crashes. For Mount & Blade, you just need to download the mod, drop it into M&B's mod folder, launch M&B, and select that mod. All done! It's simple and easy, and M&B has tons of mods. There are total conversions based around a theme, such as Star Wars, ASOIAF/Game of Thrones, Lord of the Rings, the Wild West, Viking invasions of Britan, the Napoleonic Wars, and so on.
If you just want to get a grasp of the base game, you can start your first game without any mod installed, and then if you want to amp up the complexity, you can just drop in the Diplomacy mod, and you won't even need to start a new save.
Gekokujo revamps the otherwise typically medieval setting into Sengoku period of Japan, when every clan was out for themselves. There are no shields or plate armor, horses are rare so you can't just charge through arrows anymore. You have to be conscious of the terrain. Assaulting castles are now incredibly difficult as you must have enough forces to survive climbing the steps while being rained upon by arrows. You can't hire a thousand guys anymore; you have to own at least a town or two with several businesses just to be able to pay off your army of 300+ in the field, much less the troops you keep garrisoned at your town and paroling your territory. Thus, you can't go around conquering on your own anymore. You must cooperate with the other lords to take land and to repel invasions. it takes a very long time of building slowly building up my connections with the people of the land and lords, establishing a steady cash flow, and then slowly acquiring territories and developing my properties. It feels immensely satisfying to finally become a Daiymo with six or seven towns under my belt after a couple hundred hours of play time.
Perisno revamps Mount & Blade into a fantasy setting, where in addition to humans, you can play as Tolkienish a dwarf, elf, or (my personal favorite) giant. You can also charge in with your cavalry on fantastical mounts such as mammoths or dragons.
Aside from the mechanical changes, my favorite part about Perisno is the lore. It feels like the world of Perisno is storied, and there are a lot of questchains and events that flesh out the world.
Other mod recommendations: